Surface plasmon resonance immunosensor for the detection of Salmonella typhimurium

• DOI: 10.1016/j.bios.2003.12.009
• Publication Date: 2004-01-23T05:18:16Z
• Authors: Byung-Keun Oh; Young-Kee Kim; Kwang Won Park; Won Hong Lee; Jeong-Woo Choi
• Keywords: Salmonella typhimurium; Nerve Tissue Proteins; Gold; 02 engineering and technology; Surface Plasmon Resonance; Microscopy, Atomic Force; 0210 nano-technology

An immunosensor based on surface plasmon resonance (SPR) using protein G was developed for the detection of Salmonella typhimurium. A protein G layer was fabricated by binding chemically to self-assembly monolayer (SAM) of 11-mercaptoundecanoic acid (MUA) on gold (Au) surface. The formation of protein G layer on Au surface modified with 11-MUA and the binding of antibody and antigen in series were confirmed by SPR spectroscopy. The effect of detergent such as Tween-20 on binding efficiency of antibody and antigen was investigated by SPR. The binding efficiency of antigen to the antibody immobilized on Au surface was improved up to about 85% and 100% by using protein G and Tween-20, respectively. The surface morphology analyses of 11-MUA monolayer on Au substrate, protein G layer on 11-MUA monolayer and antibody layer immobilized on protein G layer were performed by atomic force microscope (AFM). Consequently, an immunosensor based on SPR for the detection of S. typhimurium using protein G was developed with a detection range of 10(2) to 10(9)CFU/ml. The current fabrication technique of a SPR immunosensor for the detection of S. typhimurium could be applied to construct other immnosensors or protein chips.